Thursday, February 01, 2007

Repeat after me... "Natural does not always mean good."

This is a mantra that I repeat to my chemistry students, as well as to my friends and family. Just because something is natural does not mean that it is good for you. Snake venom is natural. HIV is natural. Botulinum Toxin is natural.

Chemists are learning that smaller quantities of various compounds often have greater effects than previously expected.

In this report from the New England Journal of Medicine (via cnn.com) researchers have found that lavender and tea tree oils can act as estrogen mimics in certain cases:

Lavender and tea tree oils found in some shampoos, soaps and lotionscan temporarily leave boys with enlarged breasts in rare cases,apparently by disrupting their hormonal balance, a preliminary studysuggests.

While advising parents to consider the possible risk,several hormone experts emphasized that the problem appears to happeninfrequently and clears up when the oils are no longer used. None ofthose interviewed called for a ban on sales.

The study reportedon the condition, gynecomastia, in three boys ages 4, 7 and 10. Theyall went back to normal when they stopped using skin lotions, hair gel,shampoo or soap with the natural oils.

It's unclear how often this problem might crop up in other young children.

Theseplant oils, sometimes called "essential oils," are added to manyhealth-care products, usually for their scent. The oils are sometimesfound in other household products or sold in purer forms. Tea tree oilis sometimes used in shampoos for head lice.

The suspected effectin this study is attributed to a chemical within the oils that the bodyprocesses as it does estrogen, the female hormone that promotes breastgrowth.

The findings were being reported Thursday in the NewEngland Journal of Medicine. The federally funded study came out of theUniversity of Colorado and the environmental health branch of theNational Institutes of Health. The findings were first released lastyear at a science meeting.

The three boys were brought to theirdoctors with overdeveloped breasts that looked like those of girls inearly puberty. They were sore in one case. For each boy, doctors couldtie the problem only to their use over several months of thenatural-oil products.

The researchers suspected that the oilsmight be upsetting the boys' hormonal balance. So they did a series oflaboratory tests to check how these oils work within human cells. Theoils appeared to mimic estrogen and block the male hormone androgen.

Onproduct labels, the oils sometimes are listed by their scientificnames: Lavandula angustifolia (lavender oil) and Melaleuca alternifolia(tea tree oil). Such products do not require government approval to besold unless they make specific health claims.

Marijuana and soy products also have been linked to gynecomastia.

Dr.Clifford Bloch, a hormone specialist in Greenwood Village, Colorado,who treated the three boys, recommended that parents "be cautious" withsuch products, especially for prolonged use. "I would not give theseproducts to my children," he said in an interview.

Bloch said healso suspects the oil played a role in a handful of young girls he sawfor a similar condition, including a 17-month-old whose parents werewashing her bottles with a lavender-scented soap.

Others soundedless worried. "It takes very little estrogen to cause gynecomastia in ayoung child," said Dr. Richard Auchus, a University of Texas hormoneexpert who knew of the study findings. "If they're getting it for abrief period of time, that really shouldn't cause long-term problems."

Also,the research did not pinpoint any specific estrogen-like compounds inthe oils or look for them in a range of products. Chemist StevenDentali, at the industry group American Herbal Products Association,said that warning people to avoid such oils "is premature without theadditional basic research needed to bolster the case that the issuehere is both real and significant."

Gynecomastia is very commonin boys during the hormonal changes of puberty. But it also occurs as arare condition in younger boys, men, and girls before puberty.

Bloch, the study doctor, said it's unknown if such oils could hurt women with estrogen-fed breast tumors.

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I'm crazy about search, social media and science. I'm also a husband and father to an amazing family. I dream big. I'm really interested in finding out how technology and design can make everything better.